CIRRUS

Most commercial aircraft are powered by turbojet engines.

The current trend for future turbojet engines is towards even higher bypass ratios. These UHBR (Ultra-High Bypass Ratio) engines have large fans running at relatively low speeds. As a result of these lower speeds, fuel consumption can be reduced.

Another consequence is that the engine’s noise signature is modified. Engine and fan noise will be reduced; core noise will become more significant.

In this context, the CIRRUS project aims to validate advanced low-noise concepts by developing advanced numerical and experimental tools, in order to reduce the background noise of future UHBR 2030+ turbojet engines.

Bypass ratio is one of the main indicators of turbofan efficiency. Ultra-high bypass ratio (UHBR) engines have large fans that run at relatively low speeds and therefore consume less fuel. Although high bypass ratios generate lower jet and fan noise, core noise increases.

The EU-funded CIRRUS project will combine numerical simulations and experimental work to reduce core noise for future UHBR 2030+ turbofan engines.

Another part of the work will focus on the development of acoustic coatings based on ceramic matrix composites. The proposed noise reduction concepts will be tested in real engines. Experimental measurements will be compared with theoretical ones to bring the proposed technologies to a high level of maturity (Technology Readiness Level 6).

The project behind this application has received funding from the CleanSky 2 Joint Undertaking under the European Union’s Horizon 2020 research and innovation program, under grant agreement no. 886554.